It’s a short trip from the county courthouse in downtown Gallup, N.M., and the McKinley County Sheriff’s Department on the other side of town, where officers construct policing strategies for the county. It’s a considerably longer trip from that same sheriff’s department to the Peacemaker Court in Crownpoint, N.M., on the sprawling Navajo reservation. Still, officers in McKinley County have come to utilize both of these models of justice in their work. It depends on the problem at hand.

Domestic violence is an ongoing problem in the county, as it is in many other jurisdictions nationwide. To help solve the problem, the sheriff’s department has turned to its neighbors in Crownpoint. On any weekday you are likely to find some of the peacemakers of the eastern district of the Navajo Nation working in the sheriff’s department in Gallup, helping families deal with domestic violence...